If you or someone you care about does not have health care, it's not too late to sign up for quality, affordable coverage: but you'll want to act today. The deadline to get insurance is March 31. After that, you'll have to wait until November to sign up.

Many of the people I've met have told me they were surprised at just how affordable Marketplace insurance can be. Six out of 10 uninsured Americans can get covered for $100 per month or even less — some a lot less.

In San Antonio, a family of four earning $50,000 a year can get covered for as little as $73 per month. A 27-year-old earning $25,000 can get covered for as little as $87 per month.

Security and peace of mind are just a click or call away. You may even find that you're eligible for assistance to lower the cost of your premium.

You can sign up 24 hours a day, seven days a week at HealthCare.gov (which is working smoothly) or at 800-318-2596. You can even get in-person help in your own community: Just visit localhelp. healthcare.gov and punch in your ZIP code. If you are a Spanish speaker, you can access our Spanish-language website at CuidadoDeSalud.gov and you can get in-person help in Spanish, too.

So don't delay! Join the 4 million Americans who have already signed up for a plan and the millions more who've learned they're eligible for Medicaid for this year.

Let me tell you about one of these people who lives here in Texas. On a recent visit to the Lone Star State, I met Mark Sullivan, a 31-year-old software developer. Though he was eager to start his own business, the thought of fending for himself without his employer-based health coverage made him hesitate.

But then Mark researched his options on the HealthCare. gov website. You can imagine his excitement when he found a good plan, for less than $80 a month!

Mark signed up to get covered, and now he's focused on growing his own business. “It's hard to express how much that means to me,” he told me.

Before the Affordable Care Act, hardworking families in San Antonio had few real options. Even if you worked hard and took responsibility, you could still have the rug pulled out from under you if you or someone in your family got sick, had an accident or experienced another hardship. You could pay your premium dutifully every month, only to have your insurer refuse to pay for care when you needed it most because you hit an annual or lifetime cap in coverage expenses.

But today, here in San Antonio, it truly is a new day. Thanks to the Affordable Care Act, there is choice and competition. In fact, you can now choose from 58 qualified health plans.

Unlike the old system, once you enroll, nobody can take your coverage away from you just because you get sick. And your insurance company can't charge you more just because you are a woman.

What's more, by law, insurance companies now have to cover health services such as doctor's visits, prescription drugs, ambulatory care and hospital stays. Preventive care such as cancer and cholesterol screenings are covered with no additional money out of your pocket.

But if you don't enroll by March 31, you won't get this security that comes with a Marketplace plan — and you can't enroll again until this fall.

The good news is that security for you and your family is only a click or call away: You just need to sign up by March 31 if you want Marketplace coverage this year.